Storm drain systems often include a stormwater sump or well. Some sumps are designed to allow access to the storm sewer. Some sumps serve as a junction for multiple storm drains. In some instances, the stormwater sump collects sediment for occasional removal by a refuse hauler instead of allowing the sediment to travel through the entire storm system and ultimately into a lake or river. Existing stormwater sumps often cannot retain sediments under high flow conditions and undesirably permit sediment to travel out of a sump. Systems, apparatus and methods are needed to improve sediment retention.